The invention relates to a tool for producing fiber-reinforced plastics components in an injection process, having a receptacle for a plastics component, which is surrounded by a circumferential seal that is inserted into a groove configured in the tool.
In order to produce fiber-reinforced plastics components in an injection process, tools having two shells are most often used. In order for the receptacle for the plastics component, which is located in the tool, to be sealed, an elastomer seal is employed. Injection material is filled into the receptacle during production of the plastics component. On account of volume compensation, this injection material is pressed against the seal and deforms the latter, which on account of the high temperature of the injection material and the stress on account of pressure leads to a short lifespan of the seal. This necessitates relatively frequent replacement of the seal. This in turn leads to significant material and set-up costs, and to a limited availability of the tool.
It is thus an object of the present invention to provide a tool for producing fiber-reinforced plastics components in the injection process, having a receptacle for a plastics component, which receptacle is surrounded by a circumferential seal which is inserted into a groove configured in the tool, by way of which a longer lifespan of the seal may be achieved.
This and other objects are achieved according to the invention by a tool for producing fiber-reinforced plastics components in the injection process, having a receptacle for a plastics component, which receptacle is surrounded by a circumferential seal inserted into a groove configured in the tool, in that a receptacle chamber is provided for volume compensation.
As a consequence of the design embodiment according to the invention, injection material may flow into the receptacle space without deforming and damaging the seal. This increases the lifespan of the inserted seal and, on account thereof, reduces the investment in fitting such that the availability of the tool may be increased.
According to one advantageous development, the receptacle chamber is delimited on the one side by the tool and on the other side by the seal.
If and when the tool advantageously has an upper tool part and a lower tool part, the receptacle space is advantageously delimited by the upper tool part, the lower tool part, and the seal.
According to one embodiment, the receptacle chamber on the tool side is preferably curved in a domed manner.
According to a preferred development, the seal on the side facing the receptacle chamber has a deformable wall which, in the case of an opened tool, is substantially planar and, in the case of a closed tool, is curved in a domed manner toward the receptacle chamber such that the receptacle chamber assumes a substantially lunate or crescent shape.
The seal on the wall facing the receptacle chamber advantageously has a coating of PTFE (polytetrafluoroethylene), or a similar coating. This enables simple removal of injection material which has penetrated the receptacle space.
According to one preferred development, the seal has a circular portion which is adjoined by a portion which has two parallel walls and which, on the one side, transforms into a comparatively long convex portion terminating at the wall, and on the other side transforms into a comparatively short portion which perpendicularly protrudes from the portion having the parallel walls and which is adjoined by a concave region which is opposite the wall. The concave region and the wall on the side which is opposite the circular portion are interconnected by a region which is formed by two portions of unequal length which are outwardly domed in a curved manner.
The two portions which are outwardly domed in a curved manner are preferably interconnected by a relatively short portion which is inwardly domed in a curved manner and which is opposite the center of the circular portion.
According to one advantageous embodiment, the circular portion on the side which is opposite the portion having the parallel walls has a V-shaped clearance which extends beyond the center of the circular portion.
The seal preferably is composed of EPDM (ethylene propylene diene monomer rubber), silicone, or a similar material.
According to one alternative embodiment, the seal may also be configured as a round or oval rod.
The rod may advantageously have a core from a first material, and a jacket from a second material, which surrounds the core.
According to one preferred embodiment, the jacket may be composed of PTFE or PFA (perfluoroalkoxy alkene polymer), and the core may be composed of an elastomer, such as silicone or EPDM.
The diameter of the core preferably corresponds to about half the diameter of the rod.
According to one advantageous development, the lower tool part on the side of the seal facing away from the receptacle has a plunging edge which, in the case of a closed tool, projects beyond the lower edge of the upper tool part.
Furthermore, according to an advantageous embodiment, a chamfer is provided at the transition from the lower tool part to the groove, on account of which inserting the seal into the groove is simplified.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.